Rooftop Stormwater Management
Turn your rooftop into an active stormwater retention surface
Nidaroof honeycomb panels provide on-roof temporary storage of stormwater, reducing peak discharge rates, relieving drainage networks and limiting urban runoff. Installed directly on the waterproofing membrane, each Nidaroof panel combines a drainage function with a calibrated retention capacity matched to the hydraulic requirements of the project.
This solution applies to flat roofs with raised paving slabs, roof gardens, technical rooftops and rooftop car parks — wherever on-site stormwater management is required by local planning regulations or network operators.
Choose the right Nidaroof panel for your required storage capacity
Nidaroof
Honeycomb panels for temporary storage and retention of rainwater on flat roofs and roof terraces.
Comparative table
type
Thickness
Geotextile — Face 1
Geotextile — Face 2
Storage capacity
Nidaroof 1F
40 mm - 60 mm
PET 150 g/m² (1 face only)
None
40mm = 109 L ; 60 mm = 164 L
Related case studies
See all our case studies
17 Nov. 2025
17 Nov. 2025
Why manage stormwater at roof level?
In many urban areas, regulations require on-site limitation of stormwater discharge to the public drainage network. Rooftops represent one of the largest impermeable surfaces in new-build and renovation projects.
Integrating a rooftop retention system delivers four key benefits:
- Discharge rate control — stormwater is temporarily stored within the panel structure and released progressively through a flow restrictor, reducing peak loads on the network
- Structural efficiency — the Nidaroof honeycomb structure has a 95% void ratio, adding minimal permanent load to the roof build-up
- Roof valorisation — compatible with green roofs, roof gardens, productive rooftops and technical installations
- Straightforward installation — laid directly on the waterproofing membrane, no mechanical fixing or specialist equipment required
Integrated flow regulation
Rooftop storage reduces peak discharge rates and delays runoff to the public drainage network.
Versatile applications
Flat roofs, green roofs, roof gardens, productive rooftops and rooftop car parks.
Easy installation
95% void ratio honeycomb structure — lightweight, site-cuttable, no mechanical fixing required.
Les questions fréquentes
How does a water-retentive roof system work?
Rainwater is temporarily stored within the Nidaroof honeycomb structure, which sits on the waterproofing layer. It is then released progressively through a flow restrictor, reducing runoff and relieving the stormwater network.
Which roof types are compatible with Nidaroof?
The system suits a wide range of configurations: flat roofs with raised paving slabs, trafficable and technical rooftops, green and vegetated roofs, and rooftop car parks. Its lightweight, load-bearing design allows straightforward integration on any waterproofed structural deck.
Is Nidaroof compatible with existing waterproofing systems?
Yes. Nidaroof is compatible with bituminous membranes and synthetic waterproofing systems. It integrates seamlessly into certified build-ups such as the Siplast Wateroof® system, which carries full technical approval and guarantees long-term performance.
What are the benefits for the project owner?
Managing stormwater at roof level reduces the need for below-ground storage, frees up land and adds value to the built surface. It is a cost-effective solution that meets current regulations on stormwater retention and discharge rate control.
Would you like to distribute our products?
In France, Nidaroof is distributed and installed exclusively by BMI Siplast under the certified Wateroof® system, covering the complete waterproofing and retention build-up with recognised technical approval.
For projects outside France, Nidaplast provides direct supply and full technical support to distributors, architects, design offices and project owners. Our engineering team handles hydraulic dimensioning and execution drawings from your project data.
Proven technical solutions
Our products are developed to meet real on-site requirements. Performance, reliability and durability are at the core of every solution we deliver.
Committed to reducing environmental impact
At Nidaplast, we design recyclable products, incorporate recycled materials and operate with a controlled, low-carbon manufacturing process.
Tailored support
Whether engineering specialists, design offices or sales teams, our teams support professionals through every stage of their projects — in France and internationally.
Nidaplast designs and manufactures Nidaroof honeycomb panels for stormwater management on flat roofs. Nidaroof is a polypropylene honeycomb structure with a 95% void ratio, installed on the waterproofing membrane to provide temporary stormwater storage and peak discharge rate control.
Three variants: Nidaroof 1F (40–60 mm, 109–164 L/m²), Nidaroof 100-2F (100 mm, 274 L/m²), Nidaroof 520-2F (520 mm, 1,423 L/m²).
Applications: flat roofs, green roofs, roof gardens, productive rooftops, rooftop car parks. In France: distributed exclusively by BMI Siplast (Wateroof® certified system). International: direct supply and full technical support from Nidaplast, including hydraulic dimensioning.
